Content area
Abstract
The hydrogen produced by water splitting is limited due to the high theoretical potential of the anode. So, the lower theoretical potential of the urea oxidation reaction (UOR) was selected. In this work, a highly efficient bifunctional catalyst, cobalt nitride doped with reduced graphene oxide nanosheets supported on Ni foam (Co5.47N/rGO@NF), was synthesized by hydrothermal and calcination methods for both UOR and hydrogen evolution reaction (HER). The morphology and composition of Co5.47N/rGO@NF was studied through XRD, XPS, SEM, TEM, HRTEM and elemental mapping. A parallel two-electrode electrolyzer (Co5.47N/rGO@NF||Co5.47N/rGO@NF) was constructed for electrochemical testing. To drive 100 mA/cm2, the voltage of Co5.47N/rGO@NF||Co5.47N/rGO@NF only 1.684 V is required, which is much lower than that of Pt/C||IrO2 (1.875 V) and the current density can be maintained for at least 30 h. This demonstrates that its high activity and stability have commercial feasibility.
Graphic Abstract
Details
1 College of Chemistry and Chemical Engineering, Xingtai University, Xingtai, Hebei, China
2 Xingtai University, Xingtai, Hebei, China
3 Handan Customs, Handan, Hebei, China
4 College of Chemistry and Chemical Engineering, Xingtai University, Xingtai, Hebei, China; Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China